EP1565323A1

EP1565323A1 - Safety element exhibiting properties activable by energy supply

Info

Publication number: EP1565323A1
Application number: EP03780060A
Authority: EP
Inventors: Friedrich Kastner; Matthias MÜLLER; Martin Bergsmann; Hans Hermann Kammerer
Original assignee: Hueck Folien GmbH
Current assignee: Hueck Folien GmbH
Priority date: 2002-11-28
Filing date: 2003-11-26
Publication date: 2005-08-24
Anticipated expiration: 2023-11-26
Also published as: WO2004048118A1; AU2003288173A1; ES2308001T3; DE50310260D1; ATE402827T1; EP1565323B1

Abstract

The invention relates to safety elements exhibiting properties which are activable by energy supply.

Description

Security elements with properties that can be activated by energy input

The invention relates to security elements with security features that can be activated by energy input.

Security elements are used in many areas to ensure the counterfeit security of sensitive goods. For example, such security features are used in data carriers, in particular value documents, such as ID cards, cards, banknotes, in packaging materials for sensitive goods, such as pharmaceuticals, cosmetics, electronic components, in labels, seals and the like, for example in the textile industry.

In addition, it is also desirable to manipulate packaging, e.g. Unauthorized opening of the packaging, removal or replacement of parts and the like to make it verifiable. In order to be able to provide such proof at the same time and also to be able to rule out that the security feature has been replaced, these features should also be tamper-proof.

Security elements with visually visible features are known, for example, from EP-A 0 330 733. Security elements, in particular security threads consisting of a translucent plastic film, an opaque coating which extends over the entire security element and which have cutouts in the form of the coding to be introduced, in particular in the form of characters and patterns, are described. At least in the areas defined by the cutouts, congruent coloring and / or luminescent substances may be present, by means of which the coding differs from the opaque coating under the corresponding influence of light in a color-contrasting form.

BESTATIGUNGSKOPIE Paints and varnishes with luminescent properties contain inorganic or organic pigments or dyes. The luminosity of the pigments or dyes is generally dependent on their size or their concentration, ie the higher the luminosity, the higher the pigment size or the dye concentration. Correspondingly luminous pigments or dyes are generally difficult to print due to their size or the required concentration in gravure or flexographic printing or cannot be printed with sufficient precision and resolution for use in security features. In a gravure or flexographic printing formulation, the pigments or dyes usually settle like concrete.

The object of the invention was therefore to provide security elements which have features which can be excited by the energy input to emit electromagnetic radiation.

The invention therefore relates to security elements which have security features with luminescent properties, characterized in that in order to produce a feature which can be activated by energy input, paints and / or lacquers are used which contain pigments and / or dyes or encapsulated pigments and / or dyes with a size of 0 , 1 to 50 μm or in high concentration, which can be printed using the gravure printing process.

Energy input is understood to mean both electromagnetic radiation, preferably in the range from 300 to 800 nm, direct energy supply by contact, for example by means of electrical current, inductive coupling, heat supply, or the input and conversion of kinetic energy.

Both inorganic and organic pigments or dyes which can be activated by energy input are suitable as pigments or dyes. The pigments or dyes can also be encapsulated. It can different pigments or dyes are also present side by side or encapsulated.

The pigments or dyes that can be activated by energy input can have different properties, i.e. Both luminescent, for example fluorescent or phosphorescent pigments or dyes, or else electroluminescent pigments or dyes or bioluminescent or chemiluminescent pigments or dyes can be used.

Examples of such inorganic luminescent pigments / dyes are, for example, modified barium or magesium aluminates, doped Zn sulfides or phosphorus compounds and the like.

Examples of organic luminescent pigments / dyes are, for example, anthranilic acid derivatives, oxinates, benzoxatin derivatives, europium chelates and the like.

These pigments have a size of 0.1 to 50 μm, with pigments a size of 1 to 20 μm being preferred in order to achieve high luminosity. The dyes are preferably present in a concentration of at least 5%.

The pigments and / or dyes are preferably formulated in a solvent-based concentrate with a dispersing and / or wetting agent to form a concentrate. This concentrate is compatible with a wide range of binders.

For this purpose, these pigments or dyes are formulated into a concentrate with the aid of suitable dispersing and / or wetting agents.

As a solvent, for example water come alcohol, gasoline, Shellsol ^® or their mixtures

As wetting or dispersing agents, for example, block copolymers with pigment affinic groups used as Disperk ^® 182 or 190th All conventional binders such as polyvinyl chloride, polyvinyl butyrals, polyamides, acrylates and the like can then be used as binders.

Furthermore, additional compounds can be added by the

Flow properties of the paint or varnish can be adjusted.

Examples of such compounds are silicates, fumed silica and the like.

The flow properties are set so that the ink or lacquer pigmented in this way or containing the dye can be printed using the gravure printing process.

The pigments or dyes can also be introduced in encapsulated form.

In the case of bioluminescent or chemiluminescent pigments or dyes in particular, it is advisable to introduce the two constituents which cause bioluminescence or chemiluminescence into the paint or lacquer in a separately encapsulated form. Both the substances capable of bioluminescence, for example luciferin and the like, and the enzyme which triggers bioluminescence, for example luciferase, are introduced separately in encapsulated form as a pigment into the dyeing or lacquer composition.

The encapsulation can be carried out completely separately, but so-called nested encapsulation processes can also be used, one component being encapsulated in an inner region of the entire pigment and the second component being present in the outer, surrounding part of the encapsulation. The encapsulation is then broken open, for example by friction or pressure or thermal action, the constituents can react with one another and thus generate the characteristic bioluminescence. Pigments capable of chemiluminescence are produced analogously. Examples of such pigments are chlorophyl in combination with rhodamine B.

The ink or varnish is then preferably applied to a carrier substrate by gravure printing.

The carrier substrate is, for example, carrier films, preferably flexible plastic films, for example made of PI, PP, MOPP, PE, PPS, PEEK, PEK, PEI, PSU, PAEK, LCP, PEN, PBT, PET, PA, PC, COC, POM, ABS, PVC in question. The carrier films preferably have a thickness of 5 to 700 μm, preferably 8 to 200 μm, particularly preferably 12 to 50 μm.

Furthermore, metal foils, for example Al, Cu, Sn, Ni, Fe or stainless steel foils with a thickness of 5-200 μm, preferably 10 to 80 μm, particularly preferably 20-50 μm, can also serve as the carrier substrate. The films can also be surface-treated, coated or laminated, for example with plastics, or painted.

Further, as carrier substrates also paper or composites with paper, for example, composites with plastics with a grammage 20-500 g / m ^2, preferably 40-200 g / m ^2. be used.

Furthermore, woven or non-woven fabrics, such as continuous fiber non-woven fabrics, staple fiber non-woven fabrics and the like, which can optionally be needled or calendered, can be used as carrier substrates. Such fabrics or nonwovens preferably consist of plastics, such as PP, PET, PA, PPS and the like, but woven or nonwovens made of natural, optionally treated fibers, such as viscose nonwovens, can also be used. The fabrics or nonwovens used have a weight per unit area of approximately 20 g / m ² to 500 g / m ² . If necessary, these fabrics or nonwovens can be surface-treated. The paint or varnish can be applied over the entire surface or partially, in the form of characters, patterns, geometric figures, lines and the like, using known methods.

The partial application can take place in register with one and / or more layers already present on the carrier substrate, but it can also be done completely and / or partially overlapping with one and / or more already existing layers.

The features printed in this way are transparent or translucent when viewed under white light. When excited by energy input, for example by UV radiation, the features show their characteristic radiation with high luminosity, which depending on the type of the pigment (s) can also be detected mechanically, for example by spectroscopy.

In another embodiment, different luminescent colors can be printed. It is possible to mix both fluorescent and phosphorescent colors or to print them in different layers.

Furthermore, it is particularly advantageous if the fluorescent or the phosphorescent color is only illuminated with a certain time delay. This can be achieved by dyes or pigments with a metastable energy level, such as, for example, so-called laser dyes (metastable laser-active media, such as, for example, sapphire laser, ruby laser, rare earths Nd, Y, and the like).

In a further embodiment, additional security features can be introduced by using multicolored fluorescence.

These layers, which fluoresce in different colors, can be applied over the entire surface or preferably partially. With partial Application of the layers fluorescent in different colors, if these different layers are not applied overlapping but in each case in free spaces, the pure fluorescent colors become visible.

Be in the overlap zones _. then depending on the arrangement of the different layers one above the other, however, through the additive color mixture, new color tones, clearly defined by the arrangement of the different fluorescent colors. The stimulating radiation optionally transmits into the layers below and thus generates the defined colors.

In the case of partial application with defined overlap zones in the form of patterns, lines, geometric figures, characters, letters, numbers, a grid with fully defined or partial overlap zones defined in register, additional tamper-evident features are generated by this arrangement of the layers.

In a further embodiment of the invention, the luminescent colors or lacquers can be combined with a pigment or dye reflecting in the IR spectrum. This IR-reflecting pigment or dye can be made visible using laser radiation.

For example, a red fluorescent pigment or dye can be mixed in one color or a varnish with a green IR-reflecting pigment or dye.

With an arrangement of different layers with different fluorescence and / or different IR-reflecting pigments as described above, defined color tones are also generated again, both when the fluorescence is excited and when the IR-reflecting pigments or dyes are excited, which guarantee additional security against forgery. Usually, 2 to 10 layers of this type, which may have different luminescent or fluorescent and / or IR-reflecting properties, can be printed over the entire surface or preferably partially.

3 to 5 such layers are particularly preferably applied to a carrier film.

If necessary, security features produced with such paints or varnishes can additionally represent an additional security feature by printing in different layers with at least one layer in between, one of which is a layer with different adhesive areas.

The different adhesive areas are created by applying a release layer or an adhesive layer to the carrier substrate. Known poorly adhering paint compositions, for example based on methacrylate, are particularly suitable as release layers. Furthermore, very thinly applied oil layers, PE or fluoropolymer wax layers can also be used as the release layer.

The release layer is partially applied to the carrier substrate. Any common printing process can be used to apply the release layer, preferably processes with which the thinnest layers from 0.01 to 50 μm can be applied precisely, for example spraying, vapor deposition, spreading, roller application processes, gravure, screen, offset and digital printing and like.

If the release layer is intact, a mixed color appears, for example, when viewed under excitation, and if the release layer is damaged, the pure colors become visible. If necessary, the security elements can also have termochromic, electrically conductive and / or magnetic layers and / or surface structures.

The layers can be applied by any method, for example gravure printing, flexographic printing, screen printing, digital printing and the like.

The individual features can be applied over the entire surface or partially, for example in the form of patterns, lines, letters, characters, geometric shapes, grids and the like.

Pigmented or unpigmented dye or varnish compositions can be used to apply a feature with optical properties. As pigments, all known pigments, for example pigments on an inorganic basis, such as titanium dioxide, zinc sulfide, kaolin, ITO, ATO, FTO, aluminum, chromium and silicon oxides, or pigments on an organic basis, such as phthalocyanine blue, indoliding yellow, dioxazine violet and the like, can be used as pigments colored and / or encapsulated pigments are also used in chemically, physically or reactively drying binder systems. For example, 1.1 or 1.2 come as dyes. Chromium-cobalt complexes in question.

Solvent-based paint and / or paint systems, aqueous and also solvent-free paint systems can be used.

Various natural or synthetic binders can be used as binders.

Furthermore, paints or lacquers with luminescent, for example phosphorescent or fluorescent properties, lacquers with a defined refractive index or thermochromic colors can be applied.

To apply a feature with magnetic properties, paramagnetic, diamagnetic and also ferromagnetic substances, such as Iron, nickel and cobalt or their compounds or salts (for example oxides or sulfides) or alloys of rare earth metals such as for example coblate / samarium alloys can be used.

Magnetic pigment paints with pigments based on Fe oxides, iron, nickel, cobalt and their alloys, barium or cobalt ferrites, hard and soft magnetic iron and steel types in aqueous or solvent-containing dispersions are particularly suitable. Examples of suitable solvents are i-propanol, ethyl acetate, mathyl ethyl ketone, methoxypropanol, and mixtures thereof.

The pigments are preferably incorporated in acrylate polymer dispersions with a molecular weight of 150,000 to 300,000, in acrylate-urethane dispersions, acrylate-syrene, nitrocellulose or PVC-containing dispersions or solvent-containing dispersions of this type.

The magnetic layer can, for example, also be applied partially in the form of a code, for example in the form of a so-called bar code, which can then be read out by machine, if necessary.

To apply a layer with electrical properties, the paint or lacquer to be applied, for example graphite, carbon black, conductive organic or inorganic polymers, metal pigments (for example copper, aluminum, silver, gold, iron, chromium and the like), metal alloys such as copper Zinc or copper-aluminum or amorphous or crystalline ceramic pigments such as ITO, ATO, FTO and the like can be added. Furthermore, doped or undoped semiconductors such as silicon, germanium or doped or undoped polymeric semiconductors or ion conductors such as amorphous or crystalline metal oxides or metal sulfides can also be used as additives. Furthermore, to adjust the electrical properties of the layer, polar or partially polar compounds such as surfactants or non-polar compounds such as Silicone additives or hygroscopic or non-hygroscopic salts are used or added to the paint.

If necessary, transistors can also be produced on the conductor tracks by printing technology.

A partial metal layer can also be applied as a layer with electrical properties, the partial application being able to take place by means of an etching process (application of a full-area metal layer and subsequent partial removal by etching) or by means of a demetalization process.

If a demetallization process is used, a solvent-soluble paint (if necessary in the form of an inverse coding) is applied in a first step, then the metallic layer is applied, if appropriate after activation of the carrier substrate by a plasma or corona treatment, and the soluble paint layer is then applied Treatment with a suitable solvent, including the metallization present in these areas, is removed.

Furthermore, an electrically conductive polymer layer can also be applied as the electrically conductive layer. The electrically conductive polymers can be, for example, polyaniline or polyethylene dioxythiophene.

Such a layer can also function as an antenna, wherein contact surfaces for connecting one or more microcircuits could be provided on the antenna structure.

If further information is to be stored, the antenna structure can serve as a direct contact area for conventional chip systems, conventional electronic circuits and the like. Furthermore, printed electronic circuits can also consist of electrically conductive polymers and / or vapor-deposited metallic layers and / or semiconductors in connection with conductive polymers.

Further surface relief structures, for example diffraction gratings, holograms and the like, may also be considered as additional security features, these structures possibly also being metallized or partially metallized.

To produce such surface structures, UV-curable deep-drawable lacquer is initially applied. Subsequently, for example, a surface structure can be produced by molding a die into this lacquer, which is pre-hardened to the gel point at the time of the molding, whereupon the radiation-hardenable lacquer is completely hardened after the surface structure has been applied.

By using the UV-curable lacquer, layers applied to it after curing, including any surface structure that may have been introduced, are stable even under thermal stress.

The radiation-curable lacquer can, for example, be a radiation-curable lacquer system based on a polyester, an epoxy or polyurethane system which contains 2 or more different photoinitiators which are known to the person skilled in the art and which can initiate hardening of the lacquer system to different extents at different wavelengths. For example, one photoinitiator can be activated at a wavelength of 200 to 400 nm, the second photoinitiator then at a wavelength of 370 to 600 nm. There should be enough difference between the activation wavelengths of the two photoinitiators so that the second photoinitiator is not excited too strongly takes place while the first is activated. The range in which the second photoinitiator is excited should be in the transmission wavelength range of the carrier substrate used. Electron radiation can also be used for the main curing (activation of the second photoinitiator).

A water-dilutable lacquer can also be used as the radiation-curable lacquer. Polyester-based paint systems are preferred.

Furthermore, the security elements according to the invention can be provided on one or both sides with a protective lacquer layer. The protective lacquer can be pigmented or unpigmented, all known pigments or dyes, for example TiO ₂ , ZnS, kaolin, ATO, FTO, aluminum, chromium and silicon oxides or, for example, organic pigments such as pthalocyanine blue, indolid yellow, dioxazine violet and the like can be used. Furthermore, luminescent dyes or pigments which fluoresce or phosphoresce in the visible, UV or IR range, effect pigments such as liquid crystals, pearlescent, bronzes and / or multilayer color change pigments and heat-sensitive colors or pigments can be added. These can be used in all possible combinations. In addition, phosphorescent pigments can also be used alone or in combination with other dyes and / or pigments.

Furthermore, the security element according to the invention can be provided with a hot or cold seal adhesive or a self-adhesive coating for application to the document of value to be protected or a packaging.

It is also possible to laminate the security element with a further carrier substrate, which may have further functional layers.

The security elements according to the invention are therefore, after appropriate assembly (for example to form threads, tapes, strips, patches or other formats) as security features in data carriers, in particular value documents such as ID cards, cards, Banknotes or labels, seals and the like, but also used in packaging materials for sensitive goods, such as pharmaceuticals, cosmetics, data carriers, electronic components and the like.

Claims

claims

1) Security elements with security features that have luminescent properties, characterized in that in order to produce a feature that can be activated by energy input, paints and / or lacquers are used that contain pigments and / or dyes or encapsulated pigments and / or dyes with a size of 0.1 to 50 Contain μm or in high concentration that can be printed using the gravure printing process.

2) Security elements according to claim 1, characterized in that the paint or varnishes contain pigments and / or dyes which are present in a solvent-based concentrate with a dispersing and / or wetting agent.

3) Security elements according to one of claims 1 or 2, characterized in that the paints or varnishes are fluorescent, phosphorescent, bioluminescent or chemiluminescent.

4) Security elements according to one of claims 1 to 3, characterized in that the security feature has a layer provided with an IR-reflecting pigment.

5) Security element according to one of claims 1-4, characterized in that the security feature has one or more further full-area and / or partial, in separate areas or partially and / or completely overlapping and / or register-applied functional layers with optical features

6) Security element according to claim 4, characterized in that the security element has layers with electrically conductive and / or magnetic and / or optical properties.

7. Security element according to one of claims 1-5, characterized in that the security element is provided on one or both sides with a protective lacquer layer.

8. Security element according to claim 7, characterized in that the protective lacquer layer is pigmented or not pigmented.

9. Security element according to claim 8, characterized in that the protective lacquer layer is colored and / or has luminescent or iridescent properties.

10. Security element according to one of claims 1 to 9, characterized in that it is laminated or connected to a further carrier substrate.

11. Security element according to one of claims 1 to 10, characterized in that the further carrier substrate has functional and / or decorative layers.

12. Security element according to one of claims 1 to 11, characterized in that the security elements are provided on one or both sides with an adhesive coating.

13. Security elements according to one of claims 1 to 12, characterized in that the security element additionally has a partial release layer between one or more functional layers.

4. Security elements according to one of claims 1 to 12, characterized in that the security elements are made up into threads, strips, tapes, patches and other formats.